With the development of mobile communication technology, the users' requirements are increasingly diversified. In order to meet the users' diversified requirements, private networks, such as the Home NodeB (HNB), emerge at the right moment, wherein the HNB is also referred to as a Femtocell NodeB.
There are three different access modes for the HNB: a closed mode, a hybrid mode and an open mode. The closed mode only allows a subscriber to access the cell. The hybrid mode allows all the users to access the cell, but the subscribers and non-subscribers are distinguished and then provided with different access levels and service levels. The open mode is similar to the macro cell and allows all the users to access.
As compared with the conventional macro cell, the HNB has the characteristics such as a small coverage range, a limited number of the carried users, a large quantity, an intensive deployment and a multi-layer overlap coverage. In addition, since the HNB is managed by the user rather than being an equipment controlled by the operator, it is inconvenient to perform a uniform management of the whole network. When the HNB and the macro cell use the same frequency for networking, the same frequency interference will be caused, including mutual uplink and downlink interferences between the macro cell and the HNB, due to the overlap of the network coverage of the macro cell and the HNB. Particularly, when a terminal having no right to access the HNB (i.e., a non-subscriber) approaches the HNB, the communication of the terminal will be interfered with by the strong signal of the HNB, and even a dropped call will occur. Thus, the prior art proposes to perform an interference management between the macro cell and the HNB, so as to reduce the interference to the terminal. The details are introduced as follows.
When approaching HNBs, the terminal reads a system message of an interference source HNB to acquire a cell identity of the interference source HNB, and then reports the cell identity of the interference source HNB to a Radio Network Controller (RNC) of the macro cell. The RNC finds a target HNB according to the cell identity, and notifies the HNB to adjust the transmit power, so as to reduce the interference to the terminal.
In the study and practice of the prior art, the inventor of the present invention finds that due to some factors, e.g., same frequency interference or being not supported by the capability of the terminal, the terminal cannot receive the system message of the interference source HNB (i.e., cannot acquire the cell identity of the interference source HNB), and thus cannot subsequently perform an interference management between the macro cell and the HNB, resulting in a service interruption occurring at the terminal. In addition, a certain time is spent by the terminal in reading the system message, which may also prevent the interference management from being timely carried out, and causes a drop call at the terminal.